CYLINDRICAL SECRECY MECHANISM OF LOCK FOR TUBULAR KEY Russian patent published in 1998 - IPC

FIELD: locking devices. SUBSTANCE: cylindrical mechanism of lock has body and turnable bush which is located inside body at clearance fit. Rigidly connected with bush is central core which is kinematically linked with latch of lock. Created between bush and core is annular slot to receive key. Made in body and turnable bush are coaxial radial holes which are filled with two sets of spring-biased members. First set of spring-biased members ensures locking of turnable bush with any key being inserted which is made not according to given code. Second set of spring-biased members ensures locking of turnable bush when key is removed. In this case, radial holes made in body and turnable bush filled with first set of spring-biased members are coaxial with holes in key made according to code. Turning bush and key have members which ensure displacement of lock latch as key is being rotated. Also members are provided which fix rotatable bush in axial direction relative to body. Central core is stepped. Extreme step located in front part of mechanism is larger in diameter than adjacent step which is in contact with cylindrical bosses included in sets of spring-biased members. Each set is made up of two cylindrical bosses. One of them is spring-biased, and other is supporting and is in contact with core. Made in end of supporting bosses facing towards core is cone. Angle of cone incline is not larger than incline angle of tapered surface made in key hole. Key is seated in turnable bush with clearance fit. Aforesaid embodiment of lock gives higher protection against burglary. EFFECT: higher efficiency. 4 cl, 5 dwg